The Earth’s core is changing: the consequences of a leak of a rare type of helium are named

Scientists have discovered surprising amounts of a rare type of helium called helium-3 in volcanic rocks on Canada’s Baffin Island, supporting the theory that the noble gas is leaking from the Earth’s core – and has been leaking for millennia.

The research team also found helium-4 in the rocks, CNN reported.

While helium-4 is common on Earth, helium-3 is easier to find in other parts of space, which is why scientists were surprised to find larger amounts of the element than previously reported in rocks on Baffin Island. A study describing this discovery was recently published in the journal Nature.

“At the most basic level, there is little 3He (helium-3) in the Universe compared to 4He (helium-4),” said lead study author Forrest Horton, an associate scientist in the Department of Geology and Geophysics at Woods Hole Oceanographic Institution.

“3He is rare on Earth because it was not produced or added to the planet in significant quantities, and it is lost into space,” Horton added. – As the rocky part of the Earth mixes and convects, like hot water on a slab, the material rises, cools and sinks. During the cooling stage, helium is released into the atmosphere and then into space.”

Finding elements that leak out from Earth’s core could help scientists gain insight into how our planet formed and evolved over time, and new finds provide evidence to support existing hypotheses about how our planet came to be.

Baffin Island, CNN recalls, is Canada’s largest island. It is also the fifth largest island in the world.

The high ratio of helium-3 to helium-4 was first discovered in volcanic rocks of Baffin Island by Solway Lass-Evans as part of her doctoral research under the supervision of University of Edinburgh scientist Finlay Stewart. Their results were published in the journal Nature in 2003.

A planet’s composition is a reflection of the elements that formed it, and previous research has shown that trace amounts of helium-3 leaking from Earth’s core support the popular theory that our planet originated in the solar nebula, a cloud of gas and dust that likely formed collapsed due to the shock wave from the explosion. a nearby supernova that contained that element.

Horton and his colleagues went even further when they conducted a study on Baffin Island in 2018, studying lava that erupted millions of years ago when Greenland and North America broke apart, making way for new seafloor. Scientists wanted to study rocks that may contain information about the contents contained in the Earth’s core and mantle, the main solid layer of the Earth’s interior located below its surface.

Researchers helicoptered into the island’s remote, otherworldly landscape, where lava flows have created towering cliffs, giant icebergs float by and polar bears roam the shoreline. Local organizations, including the Qikiqtani Inuit Association and the Nunavut Research Institute, provided researchers with access, advice and protection from bears, Horton said.

“This area on Baffin Island has special significance both as sacred lands for local communities and as a scientific window into the depths of the Earth,” he said.

The Arctic rocks that Horton and his team examined showed surprisingly higher levels of helium-3 and helium-4 than reported in previous studies, and the measurements varied depending on the samples they collected.

“Many lavas are full of bright green olivine (also known as the gemstone peridot), so chipping away at fresh pieces with a rock hammer was as exciting as breaking geodes as a child—each rock was a treasure to be discovered,” Horton said. “And what scientific treasures they turned out to be!”

For every million helium-4 atoms, there is only about one helium-3 atom, Horton said. The team measured about 10 million helium-3 atoms per gram of olivine crystals.

“Our measurements of high abundances of 3He/4He suggest that gases presumably inherited from the solar nebula during the formation of the solar system are better preserved on Earth than previously thought,” he said.

But how did helium-3 end up in rocks in the first place? The answer may be found back in the Big Bang, which, in creating the Universe, also released large amounts of hydrogen and helium. These elements were eventually incorporated into the formation of galaxies.

Scientists believe that our solar system formed 4.5 billion years ago within the solar nebula. According to NASA, when the dust cloud collapsed in a supernova explosion, the resulting material formed a spinning disk that eventually gave rise to our sun and planets.

Helium inherited from the solar nebula likely became trapped in the Earth’s core as the planet formed, turning the core into a reservoir of noble gases. As helium-3 leaked from the core, it rose to the surface through the mantle in magmatic plumes that eventually erupted on Baffin Island.

“During the eruption, the vast majority of the gases from the magma escaped into the atmosphere,” Horton said. “Only olivine crystals that grew before the eruption captured and stored helium from the depths of the Earth.”

A new study supports the idea that helium-3 is leaking out of the Earth’s core and has been doing so for some time, but researchers aren’t entirely sure when the process began.

“The lavas are about 60 million years old, and the rise of the mantle plume took perhaps tens of millions of years,” Horton said. “So the helium we measured in these rocks must have left the core perhaps 100 million years ago, or perhaps much earlier.”

According to him, the leak of helium from the Earth’s core does not affect our planet and does not have any negative consequences. The noble gas does not react chemically with the substance, so it will have no impact on humanity or the environment.

Next, the research team wants to find out whether the core is a repository of other light elements, which could explain why the Earth’s outer core is less dense than expected.